Range Slider: Rounding error causes values.end to exceed max

### Steps to reproduce

1.  Start the example app from the issue with Emulator **Medium_Phone Android 36.1 with Google Play** in debug mode
2.  Slide the left thumb of the RangeSlider to the right till it overlaps with the right Thumb
3. Slide the right thumb now

### Expected results

values should always be in range with valid visuals

### Actual results

- Red Screen is shown

### Code sample

<details open><summary>Code sample</summary>

```dart
import 'package:flutter/material.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatefulWidget {
  const MainApp({super.key});

  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {
  RangeValues _currentRangeValues = const RangeValues(0, 200);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: RangeSlider(
            min: 0,
            max: 200,
            values: _currentRangeValues,
            onChanged: (RangeValues values) {
              setState(() {
                _currentRangeValues = values;
              });
            },
          ),
        ),
      ),
    );
  }
}

[range_slider_bug_github.zip](https://github.com/user-attachments/files/24620974/range_slider_bug_github.zip)
```

</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

<img width="1080" height="2400" alt="Image" src="https://github.com/user-attachments/assets/290e5ea3-5695-4bb7-8d6d-3292a85a4f6b" />

</details>


### Logs

<details open><summary>Logs</summary>

```console
════════ Exception caught by widgets library ═══════════════════════════════════
The following assertion was thrown building MainApp(dirty, state: _MainAppState#db0da):
'package:flutter/src/material/range_slider.dart': Failed assertion: line 179 pos 15: 'values.end >= min && values.end <= max': is not true.

The relevant error-causing widget was:
    MainApp MainApp:file:///Users/christophprenissl/range_slider_bug/lib/main.dart:4:16

When the exception was thrown, this was the stack:
#2      new RangeSlider (package:flutter/src/material/range_slider.dart:179:15)
range_slider.dart:179
#3      _MainAppState.build (package:range_slider_bug/main.dart:22:18)
main.dart:22
#4      StatefulElement.build (package:flutter/src/widgets/framework.dart:5931:27)
framework.dart:5931
#5      ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5817:15)
framework.dart:5817
#6      StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5982:11)
framework.dart:5982
#7      Element.rebuild (package:flutter/src/widgets/framework.dart:5529:7)
framework.dart:5529
#8      BuildScope._tryRebuild (package:flutter/src/widgets/framework.dart:2750:15)
framework.dart:2750
#9      BuildScope._flushDirtyElements (package:flutter/src/widgets/framework.dart:2807:11)
framework.dart:2807
#10     BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:3111:18)
framework.dart:3111
#11     WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:1267:21)
binding.dart:1267
#12     RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:495:5)
binding.dart:495
#13     SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1430:15)
binding.dart:1430
#14     SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1345:9)
binding.dart:1345
#15     SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:1198:5)
binding.dart:1198
#16     _invoke (dart:ui/hooks.dart:356:13)
hooks.dart:356
#17     PlatformDispatcher._drawFrame (dart:ui/platform_dispatcher.dart:444:5)
platform_dispatcher.dart:444
#18     _drawFrame (dart:ui/hooks.dart:328:31)
hooks.dart:328
(elided 2 frames from class _AssertionError)

```

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel master, 3.40.0-1.0.pre-573, on macOS 26.2 25C56 darwin-arm64, locale de-DE) [1.900ms]
    • Flutter version 3.40.0-1.0.pre-573 on channel master at /Users/christophprenissl/Projects/flutter/flutter
    • Upstream repository git@github.com:flutter/flutter.git
    • Framework revision 5e417dc812 (3 hours ago), 2026-01-14 15:58:57 +0100
    • Engine revision bc63dfe662
    • Dart version 3.12.0 (build 3.12.0-17.0.dev)
    • DevTools version 2.54.0
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop, enable-android, enable-ios, cli-animations, enable-native-assets, omit-legacy-version-file, enable-lldb-debugging, enable-uiscene-migration, enable-riscv64

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [1.999ms]
    • Android SDK at /Users/christophprenissl/Library/Android/sdk
    • Emulator version 36.3.10.0 (build_id 14472402) (CL:N/A)
    • Platform android-36, build-tools 36.0.0
    • ANDROID_HOME = /Users/christophprenissl/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.8+-14196175-b1038.72)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 26.2) [4,5s]
    • Xcode at /Applications/Xcode-26.2.0.app/Contents/Developer
    • Build 17C52
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [6ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Connected device (4 available) [6,7s]
    • sdk gphone64 arm64 (mobile) • emulator-5554             • android-arm64  • Android 16 (API 36) (emulator)
    • SnakePT (wireless) (mobile) • 00008150-000104890204401C • ios            • iOS 26.2 23C55
    • macOS (desktop)             • macos                     • darwin-arm64   • macOS 26.2 25C56 darwin-arm64
    • Chrome (web)                • chrome                    • web-javascript • Google Chrome 143.0.7499.193
    ! Error: Browsing on the local area network for SnakePT. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code -27)

[✓] Network resources [250ms]
    • All expected network resources are available.

• No issues found!
```

</details>


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Range Slider: Rounding error causes values.end to exceed max #180984

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Uh oh!

Range Slider: Rounding error causes values.end to exceed max #180984

Description

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Logs

Flutter Doctor output

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